1-) 4x+6y=18
2-) -3x-7y=-16
if we want to eliminate y then we must multiply the first equation by 7 and the second one by 6
28x+42y=126
-18x-42y=-96
if we add the two equations together
28x+42y=126
(+) -18x-42y=-96
------------------------------'
10x=30
x=3
if x=3 by substituting in either equations
4x+6y=18
4(3)+6y=18
6y=6
y=1
solving the system we get (3,1) which is the only soultion
